DENSITY/SCIENTIFIC
NOTATION
UNIT 1.2 – CHAPTER 1 SECTION 2
WHY DO THINGS SINK OR FLOAT
WHAT IS DENSITY?
• Density: the amount of mass present in a volume of
matter.
• Objects with the same volume but different mass have
different densities
• Formula – Density = mass
or
volume
D= m
v
CALCULATING DENSITY
• If I have 40 grams of sugar in 120 mL of water, what
is the density?
• Remember D=m/v
• Step 1) Identify the mass m=
• Step 2) Identify the volume v=
• Step 3) Plug in and divide
CALCULATING DENSITY
• A rock has a mass of 125 kg and takes up 25 mL of
space. What is its density?
• m=
• v=
• D=
CALCULATING DENSITY
• A bucket has 40 L of salt water with a mass of 10 kg.
What is its density?
• m=
• v=
• D=
SCIENTIFIC NOTATION
• There are some really big numbers in science
• 502000000000000000000000000000000000
• There are really small numbers in science
• 0.0000000000000000000000006022
• Scientific notation is a way to write these numbers
that is simple and compact
STEPS FOR SCIENTIFIC NOTATION
• Step 1) Place the decimal so there is only 1 number
to the left
• 502000000000000000000000000000000000
• Step 2) Count the number of places the decimal
moved
•
• Step 3)Write the number as ___ x10---•
SCIENTIFIC NOTATION
• Rules:
• For really large numbers, the exponent is POSITIVE
• For really small numbers, the exponent is NEGATIVE
• Example
• 0.00000000000000000000006022
• Step 1)
• Step 2)
• Step 3)
CONVERTING TO STANDARD NUMBERS
• Rules: Move decimal point as many times as the
exponent indicates
• To the RIGHT if the number has a positive exponent
• To the LEFT if the number has a negative exponent
• Ex.) 8.3x103